(PhysOrg.com) -- By looking at the latest electronic communication devices that have emerged over the past few years, it's clear that the trend of smaller, portable devices is strong and expected to continue. Yet while all these notebooks, netbooks, and tablet PCs are becoming more and more popular, their explosive growth also poses a problem: these wireless devices are hogging the already congested lower microwave frequency region of the wireless spectrum.

This congestion problem was not unanticipated by electrical engineers, who, for the past two decades, have been developing new wireless technologies that use different parts of the electromagnetic spectrum. Specifically, these wireless technologies are exploiting the large, unused bandwidths of extremely high frequency (EHF) microwaves in the millimeter-wave (mm-wave) frequency region. One particular area of interest is the unlicensed 60 GHz frequency band, which has 5-mm wavelengths. (In contrast, the heavily burdened lower microwave regions have frequencies of 2-4 GHz, corresponding to wavelengths of 7.5-15 cm.)